void main(List<String> args) {
  getUserName(1, name: '张三', address: '北京');
  testFunc(1, city: '重庆');
}

getUserName(int id, {String? name, int? age, String? address}) {
  print('id: $id, name: $name, age: $age, address: $address');
}

testFunc(int id, {String location = '北京顺义', String city = "深圳"}) {
  print("当前的id:$id, 城市：$city, 位置: $location");
}
